In the suit, filed by Dana Redmond and William Howe, the stepchildren claim Jenner was "careless, negligent, and reckless" during the car accident, and seek unspecified damages. "The death of Kimberly Howe caused plaintiffs to suffer enormous damages and losses," the suit also reads.

In Jenner's response, filed on May 22, he says that while he agrees that the car accident was a "terrible tragedy," the plaintiffs are "financially independent and successful adult stepchildren, ages 60 and 57, living and working and residing out-of-state for decades." Therefore, the two cannot claim that they were financially dependent on their late stepmother.

Jenner has not been charged with any crime stemming from the February crash. Howe, a 69-year-old woman from Calabasas, Calif., was killed in a multi-car accident during which authorities said the Olympic gold medalist was driving north on Pacific Coast Highway in a Cadillac Escalade and rear-ended her Lexus sedan. The Lexus then veered into oncoming traffic, colliding with a black Hummer. Jenner was not injured in the crash.

Earlier this month, the stepchildren's attorneys told ET in a joint statement that part of the reason for the lawsuit is that "no one has accepted responsibility for the collision that resulted in Ms. Howe's death."

"Her children feel an obligation to bring the truth to light and seek justice for Ms. Howe," they said. "This lawsuit is the only tool at their disposal that gives them the ability to do so."